Thread tensioning device



P 1964 E. B. LINDSEY 3,146,969

THREAD TENSIONING DEVICE Filed May 10, 1962 4 Sheets-Sheet 2 E lberf B- Lindsey INVENTOR.

BY M M Sept. 1, 1964 E. B. LINDSEY THREAD TENSIONING DEVICE 4 Sheets-Sheet 4 Filed May 10 1962 Fig. /3

Elbe/f 8. Lindsay INVENTOR.

United States Patent 3,146,969 THREAD TENSIONING DEVICE Elbert B. Lindsey, 1412 Gault Ave. N., Fort Payne, Ala. Filed May 10, 1962, Ser. No. 193,814 Claims. (Cl. 242-150) This invention relates to a novel and useful thread tensioning device and more specifically to a device which is adapted to be mounted upon a knitting machine or the like and utilized to maintain a constant tension on the thread being fed to the knitting machine.

Because of the speed at which present day knitting machines operate and for other reasons the tension of the thread or yarn being fed to the machine must be held within narrow limits inasmuch as variations beyond these limits can cause the thread or yarn to break and thus the knitting machine to stop. In addition, uneven or excessive thread tension can result in breakage of the needles and thus expensive replacement and/or adjustment of certain component parts of a knitting machine. The stoppage of a knitting machine in order to correct broken thread or parts and enable necessary adjustments to be made can amount to considerable shutdown time and thus great expense. In addition, if the tension of the thread or yarn being fed to a knitting machine is not held within close limits and the thread or yarn does not break, the quality of the finished article being manufactured by the knitting machine frequently falls below acceptable standards. In addition, uneven thread tension causes the finished product such as socks to be not properly sized thereby requiring high cost in man hours of labor to sort the articles being produced into given sizes.

It is accordingly a main object of this invention to provide an adjustable thread tensioning device which will be capable of maintaining tension on thread or yarn being fed to a knitting machine within close tolerances.

A further object of this invention is to provide an adjustable thread tensioning device in accordance with the preceding objects which is constructed in a manner whereby the tensioning of the thread or yarn effected thereby may be readily adjusted throughout a predetermined range and still maintained within close tolerances.

A final object of this invention to be specifically enumerated herein is to provide a thread tensioning device in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

FIGURE 1 is a top plan view of the thread tensioning device of the instant invention;

FIGURE 2 is a side elevational view of the embodiment illustrated in FIGURE 1;

FIGURE 3 is an end elevational view on a reduced scale of the embodiment illustrated in FIGURES 1 and 2 as as seen from the left side of FIGURE 2;

FIGURE 4 is a vertical longitudinal sectional view taken substantially upon the plane indicated by the section line 44 of FIGURE 1;

FIGURE 5 is a vertical transverse sectional view taken 3,146,969 Patented Sept. 1., 1964 substantially upon the plane indicated by the section line 5-5 of FIGURE 4 and with parts of the device being broken away;

FIGURE 6 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 6-6 of FIGURE 4;

FIGURE 7 is a perspective view of an adjustable anchor arm comprising a portion of the tensioning device;

FIGURE 8 is a perspective view of the thread guiding arm assembly of the tensioning device;

FIGURE 9 is a top plan view similar to FIGURE 1 but of a modified form of tensioning device;

FIGURE 10 is a side elevational view of the embodiment illustrated in FIGURE 9;

FIGURE 11 is a fragmentary side elevational view of the tension sleeve of the device;

FIGURE 12 is a perspective View of an adjustable anchor arm comprising a portion of the modified form of thread tensioning device;

FIGURE 13 is a longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 1313 of FIGURE 9;

FIGURE 14 is a vertical transverse sectional view taken substantially upon the plane indicated by the section line 1d14 of FIGURE 10;

FIGURE 15 is a perspective view of the thrust or tension sleeve of the device; and

FIGURE 16 is a further perspective view of the tension or thrust sleeve of the device with portions thereof being displaced from their normal position to more clearly illustrate the structural details thereof.

Referring now more specifically to the drawings the numeral 10 generally designates the thread tensioning device of the instant invention. The thread tensioning device 10 includes a mounting bracket generally referred to by the reference numeral 12 and it may be seen that the mounting bracket 12 is generally U-shaped in longitudinal cross section and includes a pair of upstanding flanges or legs 14 and 16 interconnected at their lower ends by means of a bight portion 18. The mounting brackets 12 also includes a center flange or leg 20 whose lower end is secured to the bight portion 18 or formed integrally therewith as desired. The bight portion 18 of the mounting bracket 12 may be secured to any conventional portion 22 of a knitting machine by means of a suitable fastener 24 secured through a threaded aperture 26 formed in the bight portion 18.

The free end of the leg 14 is provided with a smooth bore 28 and the corresponding portion of the leg 16 is provided with a threaded bore 30. A support shaft 32 has one end portion 34 which is externally threaded and threadedly engaged in the bore 31 The free end of the threaded end of the support shaft 32 projects outwardly of the leg 16 and has a jamnut 36 threadedly engaged therewith whereby the support shaft 32 is held against rotation relative to the mounting bracket 12. However, then end of the support shaft 32 remote from the threaded end portion 34 is provided with a kerf 38 adapted to be engaged by the blade of a screwdriver or similar tool.

From FIGURES 1 and 3 through 6 it may be seen that the center leg 20 is provided with a bifurcated upper end portion defined by a pair of furcations or arms 40 and 4-2. The arm 40 is provided with a threaded bore 44 which is aligned with a smooth bore 46 formed in the arm 42. A slot 48 is defined between the free ends of the arms 40 and 42 and the inner ends of the arms 40 and 42 define a generally cylindrical pocket 50 in which a sleeve 52 is clampingly engaged by means of a fastener 54 whose shank portion is passed through the bore 46 and threadedly engaged in the bore 44. In this manner, the center leg 20 comprises a clamp for supporting the sleeve 52 in alignment with the bores 28 and 30. The sleeve 52 includes a bore 60 which rotatably and slidably receives the reduced diameter end portion 62 of a thrust and abutment sleeve 64.

The sleeve 64 is provided with a large diameter end portion 66 which is disposed outwardly of the end of the sleeve 52 adjacent the leg 14 and the confronting surfaces of the large diameter end portion 66 and the sleeve 52 are provided with inclined annular surfaces 68 and 70 whereupon rotation of the sleeve 64 relative to the sleeve 52 will effect axial displacement of the sleeve 64 relative to the sleeve 52 which is held stationary relative to the mounting bracket 12 by means of the clamp defined by the center leg 20. The sleeve 64 includes a diametric bore 72 which rotatably and slidably receives the support shaft 32 intermediate its opposite end portions and a thrust washer 74 is disposed about the support shaft 32 intermediate the large diameter end portion 66 of the sleeve 64 and the leg 14. A compression spring 76 is also disposed about the support shaft 32 and has its opposite ends engaged with the confronting surfaces of the leg 14 and the thrust washer 74.

A diametric pin 78 is passed through the end of the support shaft 32 adjacent the threaded end portion 34 thereof inwardly of the leg 16 and a thrust washer 79 is disposed about the support shaft 32 intermediate the pin 78 and the adjacent end of the reduced diameter end portion 62 of the sleeve 64.

A pair of dish shaped discs 80 and 82 are disposed about the support shaft 32 and are slidable longitudinally thereof. The discs 80 and 82 open away from each other and are disposed between the confronting surfaces of the thrust washer 79 and the free end of the reduced diameter end portion 62 of the sleeve 64.

A thread guiding arm assembly generally referred to by the reference numeral 86 is provided and may be formed of one continuous piece of rigid wire. The thread guiding arm assembly 86 includes a pair of arm portions 88 and 90 having adjacent end portions connected together by means of an integral loop 92 disposed about and secured to the end of the large diameter end portion 66 adjacent the thrust washer 74. The free ends of the arms 88 and 90 terminate in laterally directed end portions 94 and 96 respectively which each in turn terminate in eye portions 98 adapted to slidingly receive a length of yarn or thread 160. Accordingly, it may be seen that the thread guide arm assembly 86 is mounted on the sleeve 64 for rotation therewith relative to the support shaft 32. A stop arm 102 is carried by the head end of the shank 56 of the fastener 54 and extends longitudinally of the mounting bracket 12 to a position in alignment with the arm 90 whereupon rotation of the thread guide arm assembly 86 in a clockwise direction as viewed in FIGURE is limited to that position illustrated in FIG- URE 5. Of course, the arm 102 may be adjusted so as to adjust the limit of clockwise rotation of the thread guide arm assembly 86 as viewed in FIGURE 5.

With attention now directed to FIGURES 4 through 6 of the drawings it may be seen that a bore 104 is formed through the leg 20 adjacent its lower end and that a setscrew 166 is operatively associated with the bore 104. The shank portion 108 of an anchor member generally referred to by the reference numeral 110 may be secured in adjusted positions within the bore 104 by means of the setscrew 106 and one end of the anchor member 110 is provided with an eye portion 112 to which one end of an expansion spring 114 is secured, the other end of the expansion spring 114 being secured to the arm 88 in a manner to resiliently urge the thread guide arm assembly 86 in a clockwise direction towards its limit position defined by the arm 102.

Inasmuch as the shank portion 108 of the anchor member 110 may be adjusted longitudinally in the bore 104, the tension of the expansion spring 114 may be adjusted.

In operation, the thread 100 is passed through the eye portions 98 of the free ends of the arms 88 and and passed between the two discs 80 and 82. The axial thrust applied to the sleeve 64 by means of the compression spring '76 normally yieldably urges the sleeve 64 to a position rotated relative to the support shaft 32 and the sleeve 52 with the free end of the diametrically reduced end 62 of the sleeve 64 disposed closest to the pin 78 whereupon the disc 82 is urged into engagement with the disc 80 thereby compressing the thread or yarn between the two discs 80 and 82. The direction of movement of the thread 100 through the eye portions 98 is indicated by the arrows in FIGURES 1, 3 and 5 of the drawings and if the tension of the thread 100 leading to the knitting machine (not shown) is too great, the thread guide arm assembly 86 will be rotated slightly in a counterclockwise direction as viewed in FIGURE 5 of the drawings away from the limit position of clockwise rotation defined by the arm 102. This rotation of the thread guide arm assembly 86 will be transmitted to the sleeve 64 which will in turn, by means of the inclined annular confronting surfaces 68 and 70, shift the sleeve 64 axially of the support shaft 32 toward the leg 14 thereby enabling the disc 82 to move away from the pin 78 and the disc 80 lessening the compressive force effected by the discs 30 and 82 on the thread 100 and thereby the drag effected on the latter.

It is to be understood that the sleeve 52 may be shifted axially of the support shaft 32 in the clamp assembly defined by the center leg 20. In addition, the sleeve 52 may be also rotated relative to the support shaft 32 in the clamp assembly. This of course will change the spatial relationship of the free end of the diametrically reduced end portion 62 of the sleeve 64 and thus the spatial relationship of the discs 80 and 82 relative to each other. In addition, the jamnut 36 may be loosened and the support shaft 32 may be turned so as to shift the shaft 32 axially relative to the center leg 20 which fixedly supports the sleeve 52. This will also increase or decrease the spatial relationship of the discs 80 and 82.

With attention now directed to FIGURES 9 through 16 of the drawings, there will be seen a modified form of thread tensioning device generally referred to by the reference numeral which includes a mounting bracket generally referred to by the reference numeral 122 that is similar to the mounting bracket 12 but which is provided with only one pair of flanges or legs 124 and 126 interconnected by means of a bight portion 128. The bight portion 128 may also be secured to a portion 130 of a knitting machine (not shown) by means of a fastener 132 secured through the portion 130 and a threaded bore 134 formed in the bight portion 128.

The legs 124 and 126 are provided with threaded bores 136 and 138 respectively and it will be noted that the bore 138 is of a larger diameter than the bore 136. A support shaft 140 is provided and includes one threaded end portion 142 which is threadedly engaged with the bore 136 and projects through the leg 124. A jamnut 144 is secured to the threaded end portion 142 projecting outwardly of the leg 124 in order to retain the support shaft 140 against rotation relative to the mounting bracket 122.

A bearing sleeve 146 which is externally threaded as at 148 is threadedly engaged in the threaded bore 138 and rotatably receives the smooth end portion 150 of the support shaft 140. The sleeve 146 is provided with a pair of diametrically aligned bores 152 for receiving an elongated tool therethrough for effecting rotation of the sleeve 146 relative to the leg 126 for a purpose to be more fully hereinafter set forth.

A thrust sleeve 154 is rotatably disposed on the support shaft 140 intermediate the legs 124 and 126 and includes a helical slot through which an abutment pin 158 extends. The inner end of the abutment pin 158 is externally threaded as at 160 and is threadedly engaged in a threaded bore 162 which extends generally radially of the support shaft 140. The sides of the slot 156 define cam surfaces for engagement with the abutment pin 158 and accordingly, upon rotation of the sleeve 154 on the shaft 140, the sleeve 154 will be axially displaced along the shaft 140. However, as can best be seen from FIG- URES 15 and 16 of the drawings, the sleeve 154 is provided with a recess 164 which opens at one end into the slot 156 and comprises a seat for an adjustable cam 166 which is secured in the recess 164 by means of a setscrew 168. The adjustable cam 166 is provided with an arcuate slot 170 through which the threaded shank portion 172 of the setscrew 168 is slidingly received and the threaded shank portion 172 is threadedly engaged in a blind radial bore 174 formed in the sleeve 154 which opens outwardly into the recess 164. As can be seen from a comparison of FIGURES and 11, the adjustable cam 166 may be utilized to adjustably incline the cam surface 178 thereof relative to the longitudinal axis of the support shaft 140. Accordingly, the amount of axial displacement of the sleeve 154 for a given amount of rotation of the latter relative to the shaft 140 may be adjusted.

The sleeve 154 also includes a diametrically reduced end portion which is generally designated by the reference numeral 180 and which terminates a spaced distance from the inner end of the sleeve 146. A pair of discs 182 and 184 are disposed on the shaft 140 between the confronting ends of the diametrically reduced portion 180 of the sleeve 54 and the sleeve 146.

A thread guide arm assembly generally referred to by the reference numeral 186 which is substantially identical to the sleeve guide assembly 86 is secured to the sleeve 154 for rotation therewith and accordingly, it may be seen that the thread guide arm assembly 186 may be used in a manner similar to that in which the thread guide assembly 86 is used to control the spatial relationship of the discs 180 and 182 so as to vary the tension on the thread 188 passing between the discs 182 and 184.

The ends of the slot 156 define positions of rotation of the sleeve 154 relative to the support shaft 140 and in addition, the adjustable cam 166 may be also utilized to form a limit for rotational movement of the sleeve 154 in a clockwise direction as viewed in FIGURE 14.

The bight portion 128 has a bore 190 formed therethrough with which a setscrew 1% is operatively associated. The anchor member 194 includes a shank portion 196 which may be adjusted longitudinally of the bore 190 and retained in adjusted position by means of the setscrew 192 and one end of the shank 196 includes an eye portion 198 with which one end of an expansion spring 200 is engaged. The other end of the expansion spring 200 is secured to the arm 202 of the thread guide arm assembly 186 so as to normally resiliently urge the latter toward its limit position of rotation in a clockwise direction as viewed in FIGURE 14 of the drawings.

In order to adjust the spatial relationship of the discs 182 and 184 when the sleeve 154 is in its limit position of rotation in a clockwise direction as viewed in FIGURE 14, the shaft 141 may be shifted axially relative to the mounting bracket 122 by loosening of the jamnut 144 and rotation of the shaft 142 in the threaded bore 136 by means of a screwdriver or similar tool engaged with the kerf 204 formed in the smooth end portion of the support shaft 140. In addition, a suitable shank type tool may be inserted through the aligned bores 152 in order to effect rotation of the sleeve 146 which will increase the spatial relationship of the adjacent ends of the sleeve 154 and the sleeve 146.

Accordingly, it may be seen that each of the thread tensioning devices 10 and 120 may be utilized to maintain the tension on a length of thread or yarn within close tolerances and throughout a given range of adjustment of the device. In addition, the minimum spatial relationship of the discs and 82 and discs 182 and 184 may be adjusted so as to adapt the thread tensioning devices 10 and respectively to handle threads or yarns of varying diameter.

In each of the devices 10 and 120, the discs 80, 82 and 182, 184 respectively may be separated or forced apart by a knotted or diametrically enlarged portion of the thread being handled by the corresponding device. As a knot approaches the corresponding pair of discs, the knot engages the curved outer peripheral portions of those discs and tends to wedge them apart. As soon as the tension of the thread increases because of the engagement of the knot with the discs, the corresponding thread guide arm assembly will sense the increased tension and rotate in a direction effecting a reduction of the thrust eifected by the corresponding thrust or compression spring thereby enabling the discs to be more easily separated. However, if the thread is passing between the discs with sufficient speed, the devices are constructed in a manner whereby the discs may be wedged apart independently of rotation of the corresponding.,thread guide arm assembly.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1'. An adjustable thread tensioning device comprising a support shaft adapted to be supported from a knitting or sewing machine, a pair of pressure disks slidably mounted on said shaft, limit means limiting axial sliding movement of one of said disks in one axial direction along said shaft, a sleeve slidable along and rotatable on said shaft and disposed on the side of the other disk remote from said one disk, said limit means being axially adjustably positionable along the longitudinal center axis of said shaft relative to said sleeve, first means yieldably urging said sleeve in said one direction independently of rotation of said sleeve relative to said shaft and being adjustable for varying the elfective axial thrust developed thereby, a tension arm carried by said sleeve and extending transversely of and outwardly from one side of said sleeve, the free end portion of said arm including guide means adapted to slidingly guide a portion of a length of thread passing between said disks, said sleeve including first cam means, second cam means fixed relative to said shaft, said first and second cam means coacting with each other for shifting said sleeve axially of said shaft in response to rotation of said sleeve relative to said shaft, and second means normally resiliently urging rotation of said sleeve relative to said shaft independently of its axial shifting relative to said shaft and in a direction effecting axial shifting of said sleeve toward a limit position of movement in said one direction, the last mentioned means being adjustable to so as to vary the effective torque developed thereby.

2. The combination of claim 1 wherein said first cam means comprises a cam surface on said sleeve extending circumferentially thereabout and inclined along its length relative to the longitudinal axis of said sleeve.

3. The combination of claim 2 wherein said second cam means comprises an abutment adjustably fixed relative to said shaft for adjusted movement longitudinally of said shaft.

4. The combination of claim 1 wherein said first cam means comprises a cam surface on said sleeve extending circumferentially thereabout and inclined along its length relative to the longitudinal axis of said sleeve, said first cam surface including means for adjusting the inclination of said cam surface relative to the longitudinal axis of said shaft.

5. The combination of claim 1 wherein said first cam means comprises a cam surface on said sleeve extending circumferentially thereabout and inclined along its length relative to the longitudinal axis of said sleeve, said device including means for adjustably positioning said second cam means longitudinally of the longitudinal axis of said References Cited in the file of this patent UNITED STATES PATENTS Evensen Feb. 24, 1920 Heizer May 29, 1951 FOREIGN PATENTS France July 22, 1946 

1. AN ADJUSTABLE THREAD TENSIONING DEVICE COMPRISING A SUPPORT SHAFT ADAPTED TO BE SUPPORTED FROM A KNITTING OR SEWING MACHINE, A PAIR OF PRESSURE DISKS SLIDABLY MOUNTED ON SAID SHAFT, LIMIT MEANS LIMITING AXIAL SLIDING MOVEMENT OF ONE OF SAID DISKS IN ONE AXIAL DIRECTION ALONG SAID SHAFT, A SLEEVE SLIDABLE ALONG AND ROTATABLE ON SAID SHAFT AND DISPOSED ON THE SIDE OF THE OTHER DISK REMOTE FROM SAID ONE DISK, SAID LIMIT MEANS BEING AXIALLY ADJUSTABLY POSITIONABLE ALONG THE LONGITUDINAL CENTER AXIS OF SAID SHAFT RELATIVE TO SAID SLEEVE, FIRST MEANS YIELDABLY URGING SAID SLEEVE IN SAID ONE DIRECTION INDEPENDENTLY OF ROTATION OF SAID SLEEVE RELATIVE TO SAID SHAFT AND BEING ADJUSTABLE FOR VARYING THE EFFECTIVE AXIAL THRUST DEVELOPED THEREBY, A TENSION ARM CARRIED BY SAID SLEEVE AND EXTENDING TRANSVERSELY OF AND OUTWARDLY FROM ONE SIDE OF SAID SLEEVE, THE FREE END PORTION OF SAID ARM INCLUDING GUIDE MEANS ADAPTED TO SLIDINGLY GUIDE A PORTION OF A LENGTH OF THREAD PASSING BETWEEN SAID DISKS, SAID SLEEVE INCLUDING FIRST CAM MEANS, SECOND CAM MEANS FIXED RELATIVE TO SAID SHAFT, SAID FIRST AND SECOND CAM MEANS COATING WITH EACH OTHER FOR SHIFTING SAID SLEEVE AXIALLY OF SAID SHAFT IN RESPONSE TO ROTATION OF SAID SLEEVE RELATIVE TO SAID SHAFT, AND SECOND MEANS NORMALLY RESILIENTLY URGING ROTATION OF SAID SLEEVE RELATIVE TO SAID SHAFT INDEPENDENTLY OF ITS AXIAL SHIFTING RELATIVE TO SAID SHAFT AND IN A DIRECTION EFFECTING AXIAL SHIFTING OF SAID SLEEVE TOWARD A LIMIT POSITION OF MOVEMENT IN SAID ONE DIRECTION, THE LAST MENTIONED MEANS BEING ADJUSTABLE TO SO AS TO VARY THE EFFECTIVE TORQUE DEVELOPED THEREBY. 